This paper is devoted to improve the containment capacity of the Hesgoula south dumping site.The general geology of the dumping site was obtained through geological surveys.Physico-mechanical properties of silty clay ...This paper is devoted to improve the containment capacity of the Hesgoula south dumping site.The general geology of the dumping site was obtained through geological surveys.Physico-mechanical properties of silty clay and bedrock layers that have a large impact on the stability of the dump were measured by direct shear tests and triaxial tests in laboratory.Then ultimate bearing capacity of the substrate were analyzed and calculated.This paper proposed three capacity expansion and increase plans and used GeoStudio software for comparison.Through computation of the stability of the dump site slope after capacity expansion and increase for each plan,the capacity expansion plan was determined.The capacity expansion and increase plan will solve the problem of the current insufficient containment capacity of the Hesgoula south dumping site,which is of great significance for saving mine transportation costs,improving work efficiency,and reducing grassland occupation.展开更多
Coalescence among fractures would have influence on the stability of rock masses. Deep understanding of mechanical behavior of fractured rock masses is an important mean to identify failure mechanism of geological dis...Coalescence among fractures would have influence on the stability of rock masses. Deep understanding of mechanical behavior of fractured rock masses is an important mean to identify failure mechanism of geological disaster. In this study, crack propagation processing was studied through loading pre-fractured specimens of concrete block, termed as rock-like material, in uniaxial compression tests. New non-parallel double-crack geometry was introduced to observe crack coalescence. The flaw combinations are different from the normally used flaw configurations. In addition, ultrasonic detection tests were performed on the test blocks. The stress and strain data of these tests and characteristic parameters of sound wave were recorded. The stress-strain curves of each test block under the uniaxial compression test were drawn, relations among deformation characteristics and crack angle of the crack specimens, and their overall strength were analyzed. It is found that strength of the specimen decreases as crack inclination increases under two crack inclinations. The highest uniaxial compressive strength is found in the specimen with the cracks at the same angle in different directions. Based on description of the crack initiation location, crack surface and the ultimate failure patterns, failure modes of eight subtype for test blocks are divided into three categories. It is expected that the study results could be beneficial for engineering application of jointed rock masses.展开更多
The experimental model of traumatic brain injury was established in Sprague-Dawley rats according to Feeney’s free falling method.The brains were harvested at 2,6 and 24 hours,and at 3 and 5days after injury.Changes ...The experimental model of traumatic brain injury was established in Sprague-Dawley rats according to Feeney’s free falling method.The brains were harvested at 2,6 and 24 hours,and at 3 and 5days after injury.Changes in brain water content were determined using the wet and dry weights.Our results showed that water content of tissue significantly increased after traumatic brain injury,and reached minimum at 24 hours.Hematoxylin-eosin staining revealed pathological impairment of brain tissue at each time point after injury,particularly at 3 days,with nerve cell edema,degeneration,and necrosis observed,and the apoptotic rate significantly increased.Immunohistochemistry and western blot analysis revealed that the expression of occludin at the injured site gradually decreased as injury time advanced and reached a minimum at 3 days after injury;the expression of connexin 43 gradually increased as injury time advanced and reached a peak at 24 hours after injury.The experimental findings indicate that changes in occludin and connexin 43 expression were consistent with the development of brain edema,and may reflect the pathogenesis of brain injury.展开更多
基金The authors gratefully acknowledge the financial support from the National Key Research and Development Plan of China(No.2018YFC0604501)the National Natural Science Foundation of China(51674264)the Yue Qi Distinguished Scholar Project,China University of Mining&Technology,Beijing(No.800015Z1138).
文摘This paper is devoted to improve the containment capacity of the Hesgoula south dumping site.The general geology of the dumping site was obtained through geological surveys.Physico-mechanical properties of silty clay and bedrock layers that have a large impact on the stability of the dump were measured by direct shear tests and triaxial tests in laboratory.Then ultimate bearing capacity of the substrate were analyzed and calculated.This paper proposed three capacity expansion and increase plans and used GeoStudio software for comparison.Through computation of the stability of the dump site slope after capacity expansion and increase for each plan,the capacity expansion plan was determined.The capacity expansion and increase plan will solve the problem of the current insufficient containment capacity of the Hesgoula south dumping site,which is of great significance for saving mine transportation costs,improving work efficiency,and reducing grassland occupation.
文摘Coalescence among fractures would have influence on the stability of rock masses. Deep understanding of mechanical behavior of fractured rock masses is an important mean to identify failure mechanism of geological disaster. In this study, crack propagation processing was studied through loading pre-fractured specimens of concrete block, termed as rock-like material, in uniaxial compression tests. New non-parallel double-crack geometry was introduced to observe crack coalescence. The flaw combinations are different from the normally used flaw configurations. In addition, ultrasonic detection tests were performed on the test blocks. The stress and strain data of these tests and characteristic parameters of sound wave were recorded. The stress-strain curves of each test block under the uniaxial compression test were drawn, relations among deformation characteristics and crack angle of the crack specimens, and their overall strength were analyzed. It is found that strength of the specimen decreases as crack inclination increases under two crack inclinations. The highest uniaxial compressive strength is found in the specimen with the cracks at the same angle in different directions. Based on description of the crack initiation location, crack surface and the ultimate failure patterns, failure modes of eight subtype for test blocks are divided into three categories. It is expected that the study results could be beneficial for engineering application of jointed rock masses.
基金supported by the Natural Science Foundation of Guangdong Province,No.10151600101000002
文摘The experimental model of traumatic brain injury was established in Sprague-Dawley rats according to Feeney’s free falling method.The brains were harvested at 2,6 and 24 hours,and at 3 and 5days after injury.Changes in brain water content were determined using the wet and dry weights.Our results showed that water content of tissue significantly increased after traumatic brain injury,and reached minimum at 24 hours.Hematoxylin-eosin staining revealed pathological impairment of brain tissue at each time point after injury,particularly at 3 days,with nerve cell edema,degeneration,and necrosis observed,and the apoptotic rate significantly increased.Immunohistochemistry and western blot analysis revealed that the expression of occludin at the injured site gradually decreased as injury time advanced and reached a minimum at 3 days after injury;the expression of connexin 43 gradually increased as injury time advanced and reached a peak at 24 hours after injury.The experimental findings indicate that changes in occludin and connexin 43 expression were consistent with the development of brain edema,and may reflect the pathogenesis of brain injury.
